Gaseous discharge device



H FRIEDRICH- SEN GASEOUS DISCHARGE DEVICE Filed Dec. 29, 1.932

Patented Oct. 10, 1933 UNITED STATES PATENT OFFICE GASEOlJS DISCHARGEDEVICE Heinrich Friedrichsen,

Berlin-Treptow, Germany, assignor to General Electric Company, acorporation of New York 3 Glaims.

5 type.

Such devices are now known in the art in which by virtue of thestructure and arrangement of the electrodes the luminous negative glowdischarge does not completely cover the cathode but only a part thereofand said glow discharge rotates about the cathode during the operationof the device. Such a device is of great value in the advertising andsignalling arts generally. In prior devices the rotating movement of thenegative glow discharge about the cathode has not been positive and hasbeen eccentric in speed. The object of the present invention is toprovide such a device in which the rotating movement of the negativeglow discharge about the cathode is positive and of regular speed. Stillfurther objects and advantages attaching to the device and to its useand operation will be apparent to those skilled in the art from thefollowing particular description and from the appended claims.

The invention attains its objects by using an aluminum cathode having acoating of hydroxide on the discharge supporting surfaces thereof.

In the drawing accompanying and forming part of this specification anembodiment of the invention is shown in a side elevational view partlyin section.

Referring to the drawing the new and novel gaseous electric dischargedevice comprises a bulb shaped glass container 1 filled with a rare gas,such as neon, or a gas mixture, or a mixture of gas and a metal vapor.Said container 1 has a stem 2 and electrode leads 4 and 5 are sealedinto the pinch part 3 of said stem 2. Said lead 4 isconnected to theshell 6 of the base 6, 8 and said lead 5 is connected through resistance'7 to the contact button 8 of the base 6, 8. A glass tube 9 is fusedinto the pinch part 3 of the container 1 and the longitudinal axis ofsaid tube 9 is coincident with the longitudinal axis of said containerl. A mica-plate 10 rests on the top of said tube 9 and a disc 11 ofelectrically conducting material, such as iron or aluminum, is placed onsaid plate 10. Said disc 11 is connected to said lead 5 and is the anodewhen the electric discharge device operates on direct current. Amicaplate 13 of a few millimeters thickness rests on said disc 11 and acup shaped electrode 12 rests on said mica disc 13. The open end of saidelectrode 12 is closed by said disc 13. Said electrode 12 is made ofaluminum and the sides of said electrode 12 are straight in crosssection to form a cylinder and the top thereof is a hemisphere. Thecenter of said disc electrode 11 lies in the longitudinal axis of saidcup electrode 12 and in the preferred embodiment the diameter of saidelectrode 11 is greater than the largest diameter of said cathode 12 andsaid plate 13. The electrode 12 is connected to said lead 4 and is thecathode when the device operates on direct current. A threaded part ofsaid lead 4 extends through the top of said cup shaped electrode 12 andnut 14 is screwed onto said threaded part. The electrodes of the deviceare thus rigidly supported in the container 1 and the device is of veryrugged structure. A glass tube 14 insulates said electrode 11 from saidlead 4.

The external wall of the aluminum, cup shaped cathode 12 has a coatingof hydroxide thereon of molecular thickness. The hydroxide coating 15applied to said cathode 12 in the following manner. The lamp device isconnected to an exhaust pump and heated while being exhausted to extractthe water vapor from the glass walls of the container of the device. Airsaturated with water is then introduced into said container where it isallowed to remain a short time to produce an hydroxide coating on saidcathode 12 and said anode 11. The moist air is then pumped out of thedevice and the electric discharge conducting gas, such as neon, isintroduced therein after which it is sealed off.

When the negative glow electric discharge device is operated on directcurrent the negative glow discharge covers only part of the externalwall of said cathode 12 and the negative glow rotates around saidcathode 12 at a regular speed.

While I have shown and described and have pointed out in the annexedclaims certain novel features of the invention, it will be understood,that various omissions, substitutions and changes in the forms anddetails of the device illustrated and in its use and operation may bemade by those skilled in the art without departing from the spirit ofthe invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric discharge device comprising a container, a cathode and ananode sealed therein, a gaseous atmosphere therein, said cathode beingcup shaped, said anode being a disc the center thereof being in thelongitudinal axis of said cup shaped cathode, a thin plate of insulationmaterial interposed between said anode and said cathode covering theopen end of said cath- 3. An electric discharge device comprising acontainer, a cathode and an anode sealed therein, a gaseous atmospheretherein, said cathode being cup shaped, said anode being a disc thecenter thereof being in the longitudinal axis of said cup shapedcathode, the diameter of said disc anode being greater than the largestdiameter of said cup cathode, a thin plate of insulation materialinterposed between said anode and said cathode covering the open end ofsaid cathode, the external wall of said cathode having a thin hydroxidecoating thereon.

HEINRICH FRIEDRICHSEN.

